Delta wing dolphin fins described in a report in Journal of Experimental Biology and ScienceDaily 28 June 2009. A team of scientists have studied the hydrodynamic properties of the flippers of seven species of dolphin. They used computer tomography scans of the flippers to build accurate scale models of the flippers and tested these for lift and drag in a flow tunnel. The flippers varied in shape from triangular to swept pointed or swept rounded. By analysing the fluid flow around the flipper models they found that sweptback flippers generate lift like modern delta wing aircraft and hydrofoils. The researchers summarised their findings as: “we found that cetacean flippers exhibit lift and drag curves that are similar to those of modern hydrofoil control surfaces found on engineered devices.”


Editorial Comment: No-one would ride on a modern hydrofoil boat if they thought it had been left to mindless chance to make the control surfaces. People know that hydrofoils are designed by creative designers and built by clever engineers. As most hydrofoil passengers do not get to see the craft they are riding in designed and built, this belief is by faith, but it is a reasonable faith based on observations of the real world. The belief by faith that dolphin fins that work the same way were created by a smarter marine engineer is an equally reasonable faith. It is those who want naturalistic processes to do what they have never been observed to do who are unreasonable. (Ref. design, hydrodynamics, aerodynamics, mammals, cetaceans)

Evidence News 17 Feb 2010